I am wondering why USB isn't recognised at all. I followed Sparkfun Pro Micro specs. Firmware upload works fine (Adrduino Leonardo) Any help welcome !..

enter image description here

  • 1
    \$\begingroup\$ You'll need to provide a bit more detail. What's not recognizing USB? How are you flashing the firmware? \$\endgroup\$ – kolosy Nov 25 '19 at 17:30
  • 1
    \$\begingroup\$ Did you connect D+ and D- through a 22 Ohm resistor like recommended in the 32U4 datasheet? \$\endgroup\$ – StarCat Nov 25 '19 at 17:37
  • \$\begingroup\$ Plug it into a Linux box then run dmesg and edit the last dozen or so lines or anything towards the end mentioning USB into your question. \$\endgroup\$ – Chris Stratton Nov 25 '19 at 17:49
  • \$\begingroup\$ Thanks for your comments. I followed the Pro Micro specs but I think that the problem is related to the PCB routing which did not take care of USB constraints (differential pair routing). \$\endgroup\$ – Olivier Nov 27 '19 at 16:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.